What Biomechanical principles are important when successfully performing a Basketball free throw?
In today’s game of basketball, there are many
ways in which a player can score points for their respective team. Whether it is
from the three-point line or inside the key, there has always been one typical
way of scoring to be known as the easiest. This method is called a free throw
or foul shot. A free throw is an unopposed shot behind a line measuring around
4.5m from the basket. A free throw is generally awarded to a player
when they are fouled during the shooting motion or when the opposition team has
exceeded the amount of fouls allowed in one quarter of play.
As the free throw is one of the easiest ways to
score in a game of basketball, it is vastly important that players are aware of
the importance of this shot. With there being no
defenders, players are expected to make this shot quite comfortably –
especially in higher competitions (NBA). Therefore, this blog focuses on the research question,
“What biomechanical principles are important when successfully performing a
basketball free-throw?” In order to analyse this question in greater detail, there will be comparisons of various free throw techniques undertaken
by two professional basketball players. These players include DeAndre Jordan of
the Los Angeles Clippers and Stephen Curry of the Golden State Warriors.
The analysis of the skill (free-throw) and
the biomechanics involved within the skill can be separated into three separate phases. The first
phase is the initial preparation phase. This phase includes the stance of the
athlete at the free-throw line, the grip on the basketball ready to shoot the
ball and the overall stability and balance of the athlete before undergoing the shot. Phase 2
is the load phase where the athlete begins his muscle movement from the initial
positioning to where the ball is about to be released. This phase will include
the kinetic chain of movement and the angles in which the muscles are
contracting and extending. This is an important factor in a free throw as
it results in the generation of power to shoot the ball. Phases 3 refers to the
release phase and follow through of the shot. This phase will include the likes
of the shooting arm release angle and the finishing touches to the shot to
improve accuracy.
The Answer
Phase 1 – The preparation phase
Shooting Grip
Although there has been many different suggested shooting techniques in the sport of basketball, there are some key areas when shooting the basketball that many players and researchers have agreed on. When shooting a basketball there are two main points of emphasis to do with how to grip the basketball – these are the shooting hand position and the guiding hand position (Zachry, Wulf, Mercer, & Bezodis, 2005). The shooting hand (dominant hand) is used to generate the majority of the force on the ball. This hand is placed behind and slightly underneath the ball, while only letting your fingers touch the ball. The purpose behind not touching the ball with your palm is to gain backspin and improved trajectory when the ball is shot. Your fingers should be comfortably stretched apart in order to have good control of the ball. As this hand is dominantly responsible for the force generated on the ball, optimally this hand should be the last point of contact between the shooter/player and the ball. If a player's grip and release follows these guidelines, the ball will always spin backwards.
The guiding hand (non-dominant hand) is placed on the side of the ball to guide the ball in the desired (forward) direction. This hand is generally quite relaxed and makes very gentle contact with the ball. This is an important role as the guiding hand plays the sole purpose of controlling the ball and positioning it accurately when the ball is shot. When shooting a basketball it is important not to wrap your thumb around the back of the basketball as this will restrict and decrease the accuracy of the shot. A good way to know your hand is in a good position is to look at what parts of your hand you can see – you should not be able to see the back of your hand, but rather its profile, this technique can been seen below in Figure 1.
Figure 1: Shooting Grip
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| (Retrieved from: https://www.breakthroughbasketball.com/fundamentals/shooting-technique.html) |
The Benefits of Spin - The Magnus Effect
The Magnus Effect is directly related to how projectile spinning (rotating) objects are affected by air (Blazevich, 2013). The following YouTube video gives a definition of the Magnus Effect and how it can be implemented.https://www.youtube.com/watch?v=2OSrvzNW9FE
Although spin has an effect on all projectiles as they travel through the air, the Magnus effect is insignificant when performing a basketball free throw as the ball travels at a low velocity and over a short distance. In saying this, using backspin when shooting a free throw provides another benefit that differs from the Magnus effect. This benefit is related to the possibility of the ball making contact with the rim. If a basketball hits any part of the rim while spinning backwards; it is likely to deflect in a vertical direction, and therefore increasing the chance of the ball landing back through the rim/basket.
The study of free throw accuracy has been largely associated with “swishing” the ball, in which case the ball does not contact the backboard or rim (Hubbard & Okubo, 2006). This is where the importance of backspin can be seen as the ball has a very high chance of making contact with either the backboard or rim. To create optimal backspin while shooting a free throw, the player must use the grip previously explained and shown in Figure 1 above.
Shooting Stance
Like many sports that rely on stability and balance the shooting stance position consists of the player standing with their feet about a shoulder width apart (Zachry et al., 2005). This creates a larger base (area) of support, as the player now has more control over horizontal movements and is more stabilized. It is also suggested to stand with the dominant foot slightly forward so that players are not shooting across their bodies. Players also bend at the knees and slightly at the waist in order to lower their centre of gravity, as the closer the players centre of gravity is to the ground the more balanced and stable they will be. Centre of gravity can be described as the point where all particles of the body are evenly distributed, and therefore this point could be illustrated or represented by a single weight vector (Blazevich, 2013). By bending the knees players can also generate more force behind each shot. By adding both these concepts together players can become more horizontally stable and generate more vertical force.
Phase 1 - Preparation phase comparison
Figure 2 - Stance comparison
(Retrieved from: https://www.youtube.com/watch?v=5eClpi_LSqU & https://www.youtube.com/watch?v=AlQ95Y8X-lc)
Steph Curry and DeAndre Jordan's initial phases of their free throw technique can be seen in the images above. It can be seen that in general they look fairly similar, however, when each players physical characteristics are considered, the should not necessarily be using the same technique.
DeAndre Jordan is a 28 year old, 2.11m tall centre, who has one of the lowest shooting percentages in the game today (Neuharth-Keusch, 2016). Over Jordan's career (8 seasons) he has an average free throw percentage of 42% ("DeAndre Jordan", 2016). There has been instances the last few years where opposition players would intentionally foul Jordan in order to send him to the free throw line, as they believed he had a less chance of scoring points than letting his team keep the ball.
DeAndre Jordan is a 28 year old, 2.11m tall centre, who has one of the lowest shooting percentages in the game today (Neuharth-Keusch, 2016). Over Jordan's career (8 seasons) he has an average free throw percentage of 42% ("DeAndre Jordan", 2016). There has been instances the last few years where opposition players would intentionally foul Jordan in order to send him to the free throw line, as they believed he had a less chance of scoring points than letting his team keep the ball.
Steph Curry is a 28 year old, 1.91m tall point guard, who unlike Jordan, is considered one of the best free throw shooters of all time (Curtis, 2016). Curry's career (7 seasons) free throw average is just above 90% ("Stephen Curry", 2016).
The players preparation phase may look similar in the images above, however, the physical characteristics of each player must be considered. The difference in physical characteristics is important as each player is a different height, strength and weight. In this phase the height, flexibility, balance and overall strength of the players are all important contributing factors. It can be seen much more clearly in Figure 3, just how different these players physical characteristics are.
Figure 3 - Physical difference
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| (Retrieved from: https://goldengatesports.com/2014/04/28/previewing-warriors-clippers-game-5/) |
The difference between Curry and Jordan's stance in the loaded phase is important, as Curry's technique is more focussed on keeping the ball close to the body (centre of gravity). Jordan holds the ball further in front of his body, which means he needs to push his posterior out in order to remain balanced, which is further discussed in the Loaded phase. It can also be seen that Curry has his dominant (right foot) forward, which allows him to shoot the ball away from his body, rather than across it. Jordan on the other hand, is a left-handed shooter but has his right foot (non-dominant) forward. However, Jordan has been known to shoot with his left hand and dunk with his right, which could possibly mean he could be more efficient using his right hand as he chooses to put his right foot forward.
Both players have their feet about a shoulders width apart, bent knees and waist, which should be the most comfortable and stabilised position. However, the angle between the torso and upper leg (femur) of each player is significantly different. Although bending the waist can provide a lower centre of gravity and generate more force, when an angle (waist) is bent too far, it can disrupt the kinetic chain sequence through the shooting phases. This can cause loss of force (energy) is the player is bending too much. The final difference between the two players preparation phase is related to arm-width (wingspan) and where they hold the ball from the body. As Jordan's arms are longer and have more mass than Curry's (caused by gravity), it makes it hard for him to keep the ball tucked in close. This is shown by the angle between the upper arm and the torso. Curry's upper arm (humerus) is tucked in and his elbow is almost angled back to his waist (point of balance). However, Jordan's upper arm is angled away from his body and his elbow is facing towards the ground (in front of his toes).
Both players have their feet about a shoulders width apart, bent knees and waist, which should be the most comfortable and stabilised position. However, the angle between the torso and upper leg (femur) of each player is significantly different. Although bending the waist can provide a lower centre of gravity and generate more force, when an angle (waist) is bent too far, it can disrupt the kinetic chain sequence through the shooting phases. This can cause loss of force (energy) is the player is bending too much. The final difference between the two players preparation phase is related to arm-width (wingspan) and where they hold the ball from the body. As Jordan's arms are longer and have more mass than Curry's (caused by gravity), it makes it hard for him to keep the ball tucked in close. This is shown by the angle between the upper arm and the torso. Curry's upper arm (humerus) is tucked in and his elbow is almost angled back to his waist (point of balance). However, Jordan's upper arm is angled away from his body and his elbow is facing towards the ground (in front of his toes).
Phase 2 – The Loaded Phase
· The "loaded
phase" or the "set phase" of the basketball free-throw refers to
the player using various muscle groups in one sequence to generate the necessary power
in which to shoot the ball effectively.
As discussed in the previous phase, the shooting stance is a very important factor for stability and balance. Therefore, it is very important to keep the stance at shoulder width apart and to maintain a vertical descent in the knee bend. A slight lean forward from the body can help to improve body mass distribution, the shooter's centre of gravity would be lowered and a higher level of balance will be achieved. However, in this phase, the correct shooting stance will also positively effect the knee bend of the athlete and thus generate the majority of the force necessary for the free-throw. Although the arms will also produce some force, it is important to use the power from your legs to ensure the free-throw attempt is shooting in an upwards motion and a higher likelihood to be a successful shot.
As stated before, the knee bend is considered the most effective way to obtain force. This force is directly related to Newton’s Third Law of Physics - "Every action has an equal and opposite reaction" (Blazevich, 2013). In regards to a basketball free-throw, Newtons third law would refer to the downward force applied to the ground during the knee bend. The knee bend would serve as the action in the law, and the equal repelled force provided by the ground would act as the opposite reaction, which provides the upward force needed to shoot the ball. To better understand this concept, we can use other examples of sport such as tennis. For a tennis serve, the athlete wants to hit the ball at the top of his/her peak so there is an increased angle in which you can hit the ball downwards and still serve the ball inbounds. To gain this better angle, the athlete jumps into the air to hit the ball at a higher point. Therefore, the jumping action requires a downward push into the ground to obtain an opposite upward force into the air.
Although this tennis example is very similar to the basketball example, the knee bend of athletes in a basketball free throw differs due to the specific action of shooting. Tennis serves require the server to jump as high as possible to better improve the angle. Whereas, athletes performing a free throw require much less power that usually doesn’t result in them to leaving the ground. Therefore, it is important to remember, there is no optimum angle of knee bend (angle from gastrocnemius to hamstring) to ensure there is the right amount of force - it is purely focused on the comfortability of the player and the force required. The knee bend is also, somewhat dependent on the player characteristics and features. For example, a player with little muscle mass will need a smaller angle of knee bend to generate sufficient force compared to a taller player with more muscle mass. Whatever the case, force and balance achieved from the legs will always be necessary in any players’ free-throw technique.
As discussed in the previous phase, the shooting stance is a very important factor for stability and balance. Therefore, it is very important to keep the stance at shoulder width apart and to maintain a vertical descent in the knee bend. A slight lean forward from the body can help to improve body mass distribution, the shooter's centre of gravity would be lowered and a higher level of balance will be achieved. However, in this phase, the correct shooting stance will also positively effect the knee bend of the athlete and thus generate the majority of the force necessary for the free-throw. Although the arms will also produce some force, it is important to use the power from your legs to ensure the free-throw attempt is shooting in an upwards motion and a higher likelihood to be a successful shot.
As stated before, the knee bend is considered the most effective way to obtain force. This force is directly related to Newton’s Third Law of Physics - "Every action has an equal and opposite reaction" (Blazevich, 2013). In regards to a basketball free-throw, Newtons third law would refer to the downward force applied to the ground during the knee bend. The knee bend would serve as the action in the law, and the equal repelled force provided by the ground would act as the opposite reaction, which provides the upward force needed to shoot the ball. To better understand this concept, we can use other examples of sport such as tennis. For a tennis serve, the athlete wants to hit the ball at the top of his/her peak so there is an increased angle in which you can hit the ball downwards and still serve the ball inbounds. To gain this better angle, the athlete jumps into the air to hit the ball at a higher point. Therefore, the jumping action requires a downward push into the ground to obtain an opposite upward force into the air.
Although this tennis example is very similar to the basketball example, the knee bend of athletes in a basketball free throw differs due to the specific action of shooting. Tennis serves require the server to jump as high as possible to better improve the angle. Whereas, athletes performing a free throw require much less power that usually doesn’t result in them to leaving the ground. Therefore, it is important to remember, there is no optimum angle of knee bend (angle from gastrocnemius to hamstring) to ensure there is the right amount of force - it is purely focused on the comfortability of the player and the force required. The knee bend is also, somewhat dependent on the player characteristics and features. For example, a player with little muscle mass will need a smaller angle of knee bend to generate sufficient force compared to a taller player with more muscle mass. Whatever the case, force and balance achieved from the legs will always be necessary in any players’ free-throw technique.
Phase 2 - Loaded Phase comparison
Figure 4 - Load-balance comparison
(Retrieved from: https://www.youtube.com/watch?v=5eClpi_LSqU & https://www.youtube.com/watch?v=AlQ95Y8X-lc)
Above, in Figure 4,
are the load phases of elite NBA athletes, DeAndre Jordan (left) and Stephen Curry (right).
The first thing that can be noticed when comparing the two load phases is the mass distribution and
position of the players. On the right photo, we see Curry with a straight downward and upward stance. This is noticed by the vertical torso body posture and comfortable knee bend. Also, Curry still keeps the ball close to the
body allowing him to increase leverage force from his arms and chest. This could
suggest that Curry is more suited to shooting with more force from the
arms as he doesn’t always have the time to get his full knee bend during a game.
On the other side,
the mass distribution and balance of Jordan's technique seems to be unbalanced and looks uncomfortable. This
is evident as Jordan has the basketball outstretched in both hands,
considerably far from the body. Also, Jordan, relies heavily on his gluteus
maximus to be outstretched in a posterior direction to counteract his noticeable
forward lean. Any horizontal movements or leans can cause an unstable centre
of gravity.
Phase 3 – The Release Phase
In the release phase of a basketball free throw, all upper
body joints (shoulders, elbow and wrist) in the kinetic chain activate
simultaneously in one movement, creating a push-like movement pattern. This
push like pattern enables the player to create force with ease and shoot the
ball with high accuracy. Using the recommended grip shown in Figure 1, can also
increases the accuracy of a players shot. This is achieved as the dominant hand
will be pushing through the ball to generate force and the non-dominant hand
will be guiding the ball.
This pushing motion shares the same
characteristics as a boxing jab punch and a dart throw, as all of these skills
are highly reliant on accuracy. The angle and height at which the ball is
released is also a major factor in relation to the accuracy of a free throw
shot. The optimal release angle for a projectile for a projectile that both
leaves and lands on the ground (same height) is 45° (Blazevich, 2013).
However, if the release height is lower than the landing height, the angle of
the release should be a higher angle than if they were equal heights. In order to better understand this idea, we have to consider all the forces effecting the ball (net force) and that the ball has both a vertical and horizontal velocity. All forces that affect a projectile are shown in Figure 5 below.
Figure 5 - Forces that act on projectiles
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(Burkett, 2010. Sport Mechanics for Coaches: Human Kinetics.)
|
Figure 6 - Horizontal and Vertical velocities
Phase 3 - Release phase comparison
Figure 7 - Release comparison
(Retrieved from: https://www.youtube.com/watch?v=5eClpi_LSqU & https://www.youtube.com/watch?v=AlQ95Y8X-lc)
In this phase, the comparison between Jordan and Curry is difficult as there are a lot of movements that happen in a short scale of time. Curry's release is fluent as he looks to use minimal effort while shooting. The positive with not relying on generating the majority of the force with your arms while shooting is that it is easier to focus on putting backspin on the ball. Although curry does still use his arms to create force, the kinetic energy generated through his leg extension is transferred through the kinetic chain and in return the release of the ball.
Both players focus on finishing at a "high" point where after they have released the ball they are on their toes with extended arms. However, Curry's arms look much more relaxed as they aren't fully extended. Jordan's elbow joint looks to be extended almost 180 degrees (hyper-extended). This can cause tightness and strain in the kinetic chain as it can interrupt the energy transfer between the player and the ball (point of release).
Below are the links to the two videos that were used in this analysis. It is easy to see that Curry's kinetic chain and sequence of movements are fluent and comfortable. However, when analysing Jordan's release technique, it seems that he is very focussed on not exerting too much force on the ball and keeping his arms extended rather than watching the ball and the ring. It seems that Jordan's free throw technique (in general) also is not as comfortable or sequential as Curry's. As you can see in the video of Jordan, he almost shoots the ball with both hands, this can possibly have an effect on his accuracy as he doesn't push through the ball. Instead it seems like he tries to guide the ball with both hands, the more contact with the ball is said to give a player more control, however, it can sometimes been more room for error.
DeAndre Jordan: https://www.youtube.com/watch?v=AlQ95Y8X-lc
Steph Curry: https://www.youtube.com/watch?v=5eClpi_LSqU
Conclusion
· In regards to the comparison of Stephen Curry and DeAndre Jordan's free throw techniques, it is easy to recognise why Curry has a much higher success rate of free throws. This is evident
purely in the technique and fluent movement of the athlete. All movements in
Curry’s shot are relaxed and comfortable. When he shoots, no force is lost in
the kinetic chain as all muscle groups move simultaneously to provide the
appropriate force needed in his shot.
When we
watch Jordan’s free throw, it is evident that not all the muscles groups in the
chain move together. It is much more of a start and stop routing where force is
lost in all areas. However, as Jordan is a strong, athletic individual, he
still has the appropriate strength to shoot the basketball with a slight chance
of the shot going in. If Jordan can work on the fluency of his shot and reduce
the amount of force lost, he will have an increased chance of boosting
free-throw percentage.
The biomechanics used in a basketball
free throw can also be used in many other different sports. For example, a
basketball free-throw and a netball shot are both very similar movements. Also
included would be a dart throw and a boxing jab. All these movements are
similar as they are all classified as a push-like motion. What determines a
push-like motion from a throw-like movement is how all the muscles groups work
together. Because, the above movements work simultaneously in one fluent
movement, the act of these movements would be considered a push.
Furthermore, we unfortunately cannot determine the optimal release angles in
netball or basketball, because these sports need greater angles of projection
to improve shooting accuracy: the ball is much more likely to fall through the
ring/basket if it falls vertically than when it skims across the ring/basket.
References
Blazevich,
A. J. (2013). Sports biomechanics: the basics: optimizing human performance:
A&C Black.
Burkett, B. (2010). Sport Mechanics for Coaches: Human Kinetics.
Curtis, C. & Curtis, C. (2016). By the numbers: Steph Curry had the greatest season in NBA history. For The Win. Retrieved 14 June 2016, from http://ftw.usatoday.com/2016/04/stephen-curry-greatest-season-statistics
DeAndre Jordan. (2016). Basketball-Reference.com. Retrieved 14 June 2016, from http://www.basketball-reference.com/players/j/jordade01.html
Haefner,
J. (2016). Proper Basketball Shooting Technique, Fundamentals, Form,
Mechanics. Breakthroughbasketball.com. Retrieved 13 June 2016, from
https://www.breakthroughbasketball.com/fundamentals/shooting-technique.html
Hubbard, H & Okubo, M. (2006).
Dynamics of the basketball shot with application to the free throw. Journal
of sports science, 24(12), 1303.
LetsGoWarriors,. (2016). Stephen Curry shooting free throws at morning shootaround prior to Warriors-Blazers Game 4. YouTube. Retrieved 15 June 2016, from https://www.youtube.com/watch?v=5eClpi_LSqU
McGinnis, P. M. (2013). Biomechanics of Sport and Exercise: Human Kinetics.
Neuharth-Keusch, A. (2016). Ranking the NBA's worst free throw shooters of all time. USA TODAY. Retrieved 14 June 2016, from http://www.usatoday.com/story/sports/nba/2016/01/23/nba-worst-free-throw-shooters-ben-wallace-shaquille-oneal-andre-drummond/79174958/
Ramgiri, N. (2014). Previewing Warriors-Clippers Game 5. Golden Gate Sports. Retrieved 14 June 2016, from https://goldengatesports.com/2014/04/28/previewing-warriors-clippers-game-5/
Stephen Curry. (2016). Basketball-Reference.com. Retrieved 14 June 2016, from http://www.basketball-reference.com/players/c/curryst01.html
Zachry, T.,
Wulf, G., Mercer, J., & Bezodis, N. (2005). Increased movement accuracy and reduced EMG activity as the result of adopting an external focus of attention. Brain
Research Bulletin, 67(4), 304-309.
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